CHICAGO -- Almost half of those who drink coffee on the job claim they are less productive without their cup of Joe, according to a recent survey by Dunkin' Donuts and CareerBuilder.

It revealed that foodservice workers and scientists are the professions that need coffee most, among other notable workplace consumption trends.

Of the 4,100 workers surveyed nationwide, 63% who drink coffee said they consume two cups or more each workday, and 28% claimed they drink three cups or more.

The majority of younger workers said they need coffee for energy and motivation, with 62% of those aged 18 to 24 reporting that they are less productive without coffee and 58% of workers 25 to 34 making the same claim.

Fifty-five percent of workers claim to drink at least one cup of coffee each workday. By region, 64% of workers in the Northeast drink at least one cup a day, compared with 54% in the South and 51% in both the Midwest and West.

Overall, 43% of workers who drink coffee claim they are less productive without their cup of Joe; 47% of female workers claim they are less productive without coffee versus 40% of male workers.

By profession, the survey found foodservice workers are most in need of coffee, followed by scientists and sales representatives. The 10 top professions for coffee drinking are as follows, according to the survey:

"As these survey results show, coffee continues to become more and more essential in the workplace in particular, helping workers across all professions stay productive throughout the workday," said John Costello, chief global marketing and innovation officer at Dunkin' Brands.

Cynthia McIntyre, vice-president of marketing at CareerBuilder added: "There's a reason why coffee is a staple in the workplace. Workers report that coffee fuels higher energy and productivity, and serves as a means to socialize with colleagues."